The present invention relates to an impeller comprising an alloy including effective amounts of platinum, cobalt, and boron for use in a blood pump such as a rotary Ventricular Assist Device (“VAD”).
Clinical applications of Ventricular Assist Devices (“VADs”) to support patients with end-stage heart disease, as a bridge to cardiac transplantation, or as an end stage therapeutic modality have become an accepted clinical practice in cardiovascular medicine. It is estimated that greater than 35,000 persons suffering from end stage cardiac failure are candidates for cardiac support therapy.
VADs may utilize a blood pump for imparting momentum to a patient's blood thereby driving the blood to a higher pressure. In particular, a rotary VAD is a blood pump containing an electromagnetically coupled impeller that spins to assist the patient's circulatory system.
U.S. patent application Ser. No. 12/072,471, filed Feb. 26, 2008, the disclosure of which is hereby incorporated by reference into this application, provides an example of an intravascular rotary VAD that may be implanted in the patient to provide assistance in pumping blood for hearts that are afflicted with congestive heart failure or the like. This intravascular rotary VAD is a miniaturized VAD that has many uses due to it's small size. This miniaturization has made possible new techniques for less invasive implantation which in expected to shorten recovery times for patients following surgery.
U.S. Patent Application Publication No. US 2007/0078293 A1, the disclosure of which is hereby incorporated by reference provides an example of a blood pump impeller including a platinum-cobalt alloy that is magnetizable to a high degree and may be manufactured as a single piece.
U.S. Pat. No. 4,983,230, the disclosure of which is hereby incorporated by reference describes a magnetic platinum-cobalt-boron alloy having high coercivity for various uses.
By this invention, an improved blood pump impeller is provided for use in, for example, a rotary VAD. It has been found that an impeller comprising an alloy including predetermined amounts of platinum, cobalt, and boron results in an impeller that is highly effective and has superior magnetic, mechanical, and biocompatible properties. These superior properties make possible further miniaturization and streamlining of a VAD pump than has previously been impossible in the VAD industry.